title: Rapid Generation of Human-Like Neutralizing Monoclonal Antibodies in Urgent Preparedness for Influenza Pandemics and Virulent Infectious Diseases.
abstract: The outbreaks of emerging infectious diseases caused by pathogens such as SARS coronavirus, H5N1, H1N1, and recently H7N9 influenza viruses, have been associated with significant mortality and morbidity in humans. Neutralizing antibodies from individuals who have recovered from an infection confer therapeutic protection to others infected with the same pathogen. However, survivors may not always be available for providing plasma or for the cloning of monoclonal antibodies (mAbs).
  
  
  
  The genome and the immunoglobulin genes in rhesus macaques and humans are highly homologous; therefore, we investigated whether neutralizing mAbs that are highly homologous to those of humans (human-like) could be generated. Using the H5N1 influenza virus as a model, we first immunized rhesus macaques with recombinant adenoviruses carrying a synthetic gene encoding hemagglutinin (HA). Following screening an antibody phage display library derived from the B cells of immunized monkeys, we cloned selected macaque immunoglobulin heavy chain and light chain variable regions into the human IgG constant region, which generated human-macaque chimeric mAbs exhibiting over 97% homology to human antibodies. Selected mAbs demonstrated potent neutralizing activities against three clades (0, 1, 2) of the H5N1 influenza viruses. The in vivo protection experiments demonstrated that the mAbs effectively protected the mice even when administered up to 3 days after infection with H5N1 influenza virus. In particular, mAb 4E6 demonstrated sub-picomolar binding affinity to HA and superior in vivo protection efficacy without the loss of body weight and obvious lung damage. The analysis of the 4E6 escape mutants demonstrated that the 4E6 antibody bound to a conserved epitope region containing two amino acids on the globular head of HA.
  
  
  
  Our study demonstrated the generation of neutralizing mAbs for potential application in humans in urgent preparedness against outbreaks of new influenza infections or other virulent infectious diseases.
authors.affiliation: State Key Laboratory of Respiratory Disease, Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China ; The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Weixu
authors.initials: W
authors.lastname: Meng
authors.forename: Weiqi
authors.initials: W
authors.lastname: Pan
authors.forename: Anna J X
authors.initials: AJ
authors.lastname: Zhang
authors.forename: Zhengfeng
authors.initials: Z
authors.lastname: Li
authors.forename: Guowei
authors.initials: G
authors.lastname: Wei
authors.forename: Liqiang
authors.initials: L
authors.lastname: Feng
authors.forename: Zhenyuan
authors.initials: Z
authors.lastname: Dong
authors.forename: Chufang
authors.initials: C
authors.lastname: Li
authors.forename: Xiangjing
authors.initials: X
authors.lastname: Hu
authors.forename: Caijun
authors.initials: C
authors.lastname: Sun
authors.forename: Qinfang
authors.initials: Q
authors.lastname: Luo
authors.forename: Kwok-Yung
authors.initials: KY
authors.lastname: Yuen
authors.forename: Nanshan
authors.initials: N
authors.lastname: Zhong
authors.forename: Ling
authors.initials: L
authors.lastname: Chen
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis* / Q000276:immunology; D057134:Antibodies, Neutralizing / Q000096:biosynthesis* / Q000276:immunology; D021821:Communicable Diseases, Emerging / Q000453:epidemiology / Q000276:immunology / Q000628:therapy*; D004196:Disease Outbreaks; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology; D007251:Influenza, Human / Q000453:epidemiology / Q000276:immunology / Q000628:therapy*; D008253:Macaca mulatta; D051379:Mice
chemical_list: D000911:Antibodies, Monoclonal; D057134:Antibodies, Neutralizing